In a development with potential implications for treating not only AIDS but also other viral infections like hepatitis C and the common cold, US scientists have successfully completed the first map of the entire genome of HIV.

"We are beginning to understand the tricks the genome uses to help the virus escape detection by the human host," said Kevin Weeks, a professor at the University of North Carolina-Chapel Hill and the study's leader.

HIV - like the viruses that cause polio, influenza, and hepatitis C - stores its genetic information in single-strand RNA rather than the double-strand DNA common to all living organisms and some other viruses. Unlike DNA, RNA can manipulate itself into complex, three-dimensional patterns, making it very difficult to decode.

Earlier mapping efforts have successfully modeled small parts of the HIV genome, but Weeks and colleagues used a new technique that produced lower-resolution images of a greatly expanded area.

Weeks hopes the knowledge contained in the complete map will guide scientists in developing effective attacks against HIV, potentially by creating an entirely new class of drugs.

"Structural biologists can now use this genomic map to judiciously zoom in on pieces of the HIV-1 genome and determine architectural and functional principles at the atomic level," said an accompanying commentary by Hashim Al-Hashimi of the University of Michigan.

The study, "Architecture and Secondary Structure of an Entire HIV-1 RNA Genome," and the commentary, "Structural Biology: Aerial View of the HIV Genome," were published in Nature (2009; doi:10.1038/nature08237 and doi:10.1038/460696a).